Catapult delivery device



4 Sheets-Sheet 1 Filed July 15, 1963 M M H MM W W2 M 87 7 N V B Q June 23, 1964 A. R. LARDIN 3,133,063

CATAPULT DELIVERY DEVICE 4 Sheets-Sheet 2 Filed July 15, 1963 INVENTOR'. I4 Z/7/MZ e Aka/M June 23, 1964 A. R. LARDIN 3,133,063

CATAPULT DELIVERY DEVICE Filed July 15, 1963 4 Sheets-Sheet 3 & wt

SQNK 9% M6 MQQ ArrazMf/ June 23, 1964 A. R. LARDIN CATAPULT DELIVERY DEVICE 4 Sheets-Sheet 4 Filed July 15, 1963 NUEK INVENTOR. 4F 7/d/Z ZA/ZD/A/ United States Patent C) 3,138,063 CATAPULT DELIVERY DEVICE Arthur R. Lardin, Monmouth Mobile Home Park, US. Highway 1, Monmouth Junction, NJ. Filed July 15, 1963, Ser. No. 295,081 9 Claims. (Cl. 89-1) This invention relates to a catapult delivery device and more particularly to a device capable of launching or hurling an object or store for a substantial distance.

Catapults as they have been known throughout history have relied upon the recoil of a spring in one form or another to project objects with great force in a generally desired direction. Certain catapults resembled crossbows and were necessarily slow to operate and of limited power. Other catapults more particularly called slings were in the form of a large beam pivotally secured at one end and provided with some object retaining sling at the opposite end. The beam was then pulled down against the tension of some springlike device and released with the result that the object was propelled in the generally desired direction. However, such slings required that the object be held down throughout the major portion of travel in order to prevent the object from flying off as a result of centrifugal force. In addition, a large amount of the force imparted to the sling was lost in the form of the friction due to restraining the object against centrifugal force and could not contribute to the launching of the object.

Accordingly, it is an object of the present invention to provide a catapult delivery device capable of launching an object through the air with a great amount of force and accuracy. Such devices are capable of throwing food, supplies and cable across rivers, ravines, or impassable places. In addition, catapults made in accordance with the present invention are capable of delivering incendiary or corrosive materials in certain types of warfare.

A further object of the present invention is to provide a catapult delivery device which is simple in structure, easy to load, and light enough to be moved from place to place by means of small vehicles or tanks.

Another object of the present invention is to provide a catapult delivery device which may be aimed with a high degree of accuracy, and which will not destroy the store in launching.

Another object of the present invention is to provide a catapult device capable of rapid and repeated delivery operations.

A feature of the present invention is its use of a novel piston and linkage arrangement for projecting an object through the air.

Still another feature of the present invention is its use of a gas expansion motor as the propelling force.

A further feature of the present invention is its compact highly mobile construction.

Still another feature of the present invention is its highly simplified troublefree construction.

The invention consists of the construction, combination,

and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawing, forming a part hereof is illustrated one form of embodiment of the invention, and in which:

FIGURE 1 is a view in side elevation partially broken away showing one complete embodiment of the present invention.

FIGURE 2 is a top plan view taken on line 22 in FIGURE 1, with certain parts broken away for the sake of clarity.

FIGURE 3 is a view similar to FIGURE 1 showing the 3,l38,53 Patented June 23, 1964 ice led

catapult delivery device in the launch position with the frame illustrated in dashed lines for the sake of clarity.

FIGURE 4 is a fragmentary front elevational view showing the launching cradle and bottom of the frame according to the present invention.

FIGURE 5 is a cross-sectional view taken on line 55 of FIGURE 2, looking in the direction of the arrows.

FIGURE 6 is a view in longitudinal section of the driving piston shown on an enlarged scale.

FIGURE 7 is a somewhat diagrammatic view showing constituting a force diagram of a sling in accordance with the prior art.

FIGURE 8 is a view similar to FIGURE 7 showing the forces involved and the action of the present invention.

FIGURE 9 is a fragmentary view of a portion of the shock absorbing structure of the present invention.

Referring to the drawings and particularly to FIG- URES 1, 2, and 3, 10 indicates a catapult delivery device built upon a frame 11 which supports spaced driving links 12 and a launching arm 13.

Power is imparted to the driving links 12 by a gas expansion motor 14 consisting of a cylinder 15, a piston 16 and a cartridge receiving gas expansion chamber 17. The other end 18 of the piston 16 is pivotally secured to the driving links 12 at a point intermediate the ends thereof. The driving links 12 are pivotally secured at their lower end by pin 46 to the spaced side frames 19 of the frame 11 and are coupled to the launching arm 13 by means of the trunnion 40 journaled in bearing 20 spaced from its upper end.

An elongated track 21 consisting of spaced guide members 22 is secured to the inner face of each of the spaced side frames 19. A transverse roller 23 is slidably carried within the tracks 21 as shown in FIGURE 2. A forked segment 24 is journaled to the roller 23 and slidably moves with it between the said frames 19. The outer end of the segment 24 is secured to the inner end. of the launching arm 13 as best shown in FIGURES 2 and 3. Thus, as the roller 23 and the segment 24 move up and down the tracks 21 they carry with them the inner end of the launching arm 13.

The outer end of the launching arm 13' is coupled to a launching cradle 25. The cradle 25 is adapted to receive a store, barrel, or other object which is to be propelled through the air and which is generally indicated in dashed lines in FIGURES 1 and 3 at 26. The cradle 25 is pivotally connected to the outer end of the launching arm 13 by means of the pin 27 and the travel of the cradle is controlled by a trapezoidal linkage 28 which is connected at one end to each side of the cradle 25 and at its inner ends to two spaced stub shafts 29 as shown in FIGURE 2. The stub shafts 29 in turn are carried by spaced links 12 and extend through forked members 34 secured to the ends of elongated return arms 31 which in turn are attached to a return shock absorber 32.

The return shock absorber 32 is pivotally attached to the frame 11 near the upper end thereof. It is within the purview of the present invention to substitute another shock absorbing means such as elastic cable for the shock absorber 32 and the shock absorber 44 illustrated in FIGURE 9.

The thrust necessary to hurl the object from the cradle 25 along the desired path 48 (see FIGURES 3 and 8) is provided by the gas expansion motor 17 shown in FIG- URES 1 and 3. The motor consists of a block 33 suitably bored to receive therein a cartridge 34. A bore 35 leads from the cartridge receiving chamber into the cylinder 15 of the motor 14. The piston 16 of the gas expansion motor 14 is hollowed out as indicated at 36 in FIGURE 6 for the greater part of its length to provide a gas expansion chamber for the expanding gases passing through the bore 35 of large initial volume. In this manner the maximum forces applied by the expanding gases are substantially more evenly distributed throughout the stroke and deflection of the elongated piston is minimized. The force of the expanding gases is also applied more directly to the driving link 12 where it is journaled to the piston 16. A more even distribution of the forces of the expanding gases is also achieved by means of this construction. As a preferred example with a charge of 166 grams of smokeless powder the volume required of the expansion chamber initially is 60 cubic inches to produce an initial gas pressure of 24,000 psi. and also result in an average gas pressure of 11,600 psi. The ratio of the initial volume to final volume is 0.32.

In mechanical prior art catapults a peak force of exactly twice the average force is required to produce the total energy.

In the case of the expanding gas prior art catapults a peak force of many times the average force is required to produce the total energy.

In the case of the expanding gas plus the integrating linkage catapult as described herein, a peak force approximately equal to the average force is available to produce the total energy. Also, in the case of the present application a peak force slightly higher than the average force is introduced through the linkage system to apply toward the end of the displacement stroke.

From the above it can be seen that this invention will produce identical results with a peak force exactly onehalf the magnitude inherent in the mechanical catapult and many times less than the magnitude inherent in the expanding gas type of catapult.

This result is important because of the need to launch fragile projectiles in combat and for supply purposes.

By way of illustration, one proposed projectile is subiect to an acceleration of 70 Gs during launch with the expanding gas, integrating linkage, catapult whereas it would be subject to a peak of 140 GS during launch with a mechanical catapult, or a peak of 305 GS during launch with a pure expanding gas catapult (a mortar).

In addition to the above, the basic equation for velocity increase involves the expression (V V However, the prior art catapults supply their maximum forces exactly contrary to the force variation suggested by the expression (V V By applying the integrating linkage concept to the expanding gas force characteristics, a force vs. velocity increase curve is possible where the force available increases as the velocity increases. In the present invention this force increase is adjusted by the geometry of the linkage system to produce a substantially constant acceleration, on the projectile.

In order to withstand the reactive forces operating during the launch, the bottom of the frame is provided with a claw or toothed portion 37 which will dig into the ground or support of the launcher and hold it in place. Mobility is added to the launcher by means of Wheels 38 which are mounted to the frame by means of struts 39. It will be apparent that the catapult launcher can be tipped into a substantially horizontal position after firing for towing purposes.

Referring to FIGURES l and 2, the operation of the catapult will become apparent. Starting with the catapult in the position shown in FIGURE 1 and with the store in place, a cartridge 34 is slipped within the gas expansion chamber 17 of the motor 14. When the cartridge 34 is fired by any well known means, the piston 16 will be driven from the position shown in FIGURE 1 to that illustrated in FIGURE 3. As the piston 16 moves outwardly it causes the driving links 12 to rotate about their pivot points, the pin 46, upon the frame members 19. The bearing 20 on the upper portion of each of the driving links 12 embrace a trunnion 40 on the launching arm 13 and, as the driving links swing from the position shown in FIGURE 1 through an arc to the position shown in FIGURE 3, the launching arm 13 is powerfully accelerated. As the launching arm 13 is lifted the roller 23 at the inner end of the said arm moves down the tracks 21 to the position shown in FIGURE 3.

As the piston 16 reaches the end of its travel, the gas within the cylinder is ported through an opening 41 in the side of the cylinder so that the piston 16 is relieved of its driving force. The return shock absorber thereupon takes over and pulls the launching arm and driving link back to its original position shown in FIGURE 1. At the end of the travel shown in FIGURE 3 the store 26 will be hurled from the cradle 25 in the path of its trajectory 48.

A shock absorber 44 such as a hydraulic shock absorber is located adjacent the bottom of each track 21. A sliding block 45 having an arcuate seat 47 on the top thereof is secured to the top of the shock absorber and is guided by the rails 22 of the track 21. The opposite end of the shock absorber is journaled upon the transverse pin 46 which spans the frames 19. The impact of the roller 23 as it reaches the end of its travel is absorbed by the shock absorber 44.

Referring to FIGURE 7 there are shown the forces exerted in a sling made in accordance with well known structures. It will be noticed from this diagram that the load tends to fly outwardly in a direction indicated by arrows 42 due to the action of centrifugal force. Accordingly, in order to keep the load in the desired path of travel indicated at 43 it is necessary to restrain the load until it reaches the desired direction of launch force. The result of this limitation is to greatly reduce the amount of force available to hurl the load or object.

In contrast, in FIGURE 8, there are shown the forces involved in a catapult launcher made in accordance with the present invention. It will be seen that as the launching arm 13 is driven by the driving links 12 the cradle, indicated by the letter C will move along a line indentical with the desired direction of launch. Since this is a straight line all of the power imparted by the gas expansion motor 14 Will be expended in the task of hurling the load or store.

From the foregoing it will be seen that there has been provided a catapult launching device capable of hurling an object with the maximum amount of efiiciency for its given power input and with great accuracy. The device is simple in structure, easy to load, and capable of repeated use without failure. Despite its use of the gas expansion type motor, its rugged construction and piston configuration whereby all of the power is applied directly to the driving link provides a minimum amount of deflection and a maximum of power transmission. The launching device provides a peak acceleration which is substantially equal to the average acceleration imparted to the store or object launched. As a result, objects which would be destroyed during initial launch velocities of prior art devices remain unharmed, as they leave the launcher.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

l. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, spaced driving links swingably secured at one end to the frame, a launching arm se cured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a gas expansion motor secured to the frame, a gas expansion chamber of large initial volume with respect to final volume in said motor, and in driving engagement with the driving links to swing the links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

2. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm,, a cradle carried by the free end of the launching arm, a trapezoidal linkage secured at one end to the cradle and at its other end to the frame members to control the cradle travel, a gas expansion motor secured to the frame, a gas expansion chamber of large initial volume with respect to final volume in said motor, and in driving engagement with the driving links to swing the links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

3. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a trapezoidal linkage secured at one end to the cradle and at its other end to the frame members to control the cradle travel, shock absorbing means between the frame and the cradle, a gas expansion motor secured to the frame, a gas expansion chamber of large initial volume with respect to final volume in said motor, and in driving engagement with the driving links to swing the links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

4. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a trapezoidal linkage secured at one end to the cradle and at its other end to the frame members to control the cradle travel, shock absorbing means comprising a shock absorber attached at one end of the frame members and at least one elongated return arm secured to the shock absorber at its free end and to the trapezoidal linkage at the other end between the frame and the cradle, a gas expansion motor secured to the frame, a gas expansion chamber of large initial volume with respect to final volume in said motor, and in driving engagement with the driving links to swing the links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

5. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, shock absorbers coupled to the frame members and extending into each of the tracks at the bottom thereof to receive the transverse roller at the end of the travel, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a gas expansion motor secured to the frame, a gas expansion chamber of large initial volume with respect to final volume in said motor, and in driving engagement with the driving links to swing the links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

6. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end Within the tracks, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a gas expansion motor, a cylinder within the motor, a piston slidable within the cylinder, a gas expansion chamber of large initial volume with respect to final volume in said motor, a piston rod secured at one end to the piston and coupled at its opposite end to the driving links to swing the said links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

7. A device according to claim 6 in which the piston and piston rod are formed with a continuous internal bore to receive the expansion gasses of the motor.

8. A catapult store delivery device comprising spaced frame members, an elongated track on the inner face of each frame member, a transverse roller slidably carried at each end within the tracks, shock absorbers coupled to the frame members and extending into each of the tracks at the bottom thereof to receive the transverse roller at the end of its travel, spaced driving links swingably secured at one end to the frame, a launching arm secured at one end to the transverse roller and coupled to the free ends of the driving links at a point intermediate the ends of the said arm, a cradle carried by the free end of the launching arm, a trapezoidal linkage secured at one end to the cradle and at its other end to the frame members to control the cradle travel, shock absorbing means comprising a shock absorber attached at one end to the frame members and at least one elongated return arm secured to the shock absorber at its free end and to the trapezoidal linkage at the other end between the frame and the cradle, a gas expansion motor, a cylinder within the motor, a piston slidable Within the cylinder, a piston rod secured at one end to the piston, a gas" expansion chamber of large initial volume with respect to final volume in said motor and coupled at its opposite end to the driving links to swing the said links and drive the free end of the launching arm upward to lift the cradle in a straight line path and launch the store.

9. A device according to claim 6 in which the piston and rod are formed with a continuous internal bore to receive the expanding gasses of the motor and the ratio of the initial volume of said bore with respect to the final volume of the motor bore is of the order of 0.32.

References Cited in the file of this patent UNITED STATES PATENTS 3,008,376 Brunow et a1. Nov. 14, 1961 

1. A CATAPULT STORE DELIVERY DEVICE COMPRISING SPACED FRAME MEMBERS, AN ELONGATED TRACK ON THE INNER FACE OF EACH FRAME MEMBER, A TRANSVERSE ROLLER SLIDABLY CARRIED AT EACH END WITHIN THE TRACKS, SPACED DRIVING LINKS SWINGABLY SECURED AT ONE END TO THE FRAME, A LAUNCHING ARM SECURED AT ONE END TO THE TRANSVERSE ROLLER AND COUPLED TO THE FREE ENDS OF THE DRIVING LINKS AT A POINT INTERMEDIATE THE ENDS OF THE SAID ARM, A CRADLE CARRIED BY THE FREE END OF THE LAUNCHING ARM, A GAS EXPANSION MOTOR SECURED TO THE FRAME, A GAS EXPANSION CHAMBER OF LARGE INITIAL VOLUME WITH RESPECT TO FINAL VOLUME IN SAID MOTOR, AND IN DRIVING ENGAGEMENT WITH THE DRIVING LINKS TO SWING THE LINKS AND DRIVE THE FREE END OF THE LAUNCHING ARM UPWARD TO LIFT THE CRADLE IN A STRAIGHT LINE PATH AND LAUNCH THE STORE. 